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SN65HVD1040: SN65HVD1040 gets no output signal problem

Sheldon He
Expert 8585 points
Part Number: SN65HVD1040

Hi expert,

My customer use SN65HVD1040 in their UPS system. Recently they reported one single case which SN65HVD1040 do not give any output signal when MCU sending data to it. After they replace the "failure IC" with another one, problem solved. This "failure IC" can reproduce this problem in other boards.

We have already run a FA and no problem is reported on this "failure IC".

Do you have any idea on how to do a debug at field?

Thanks

Sheldon

  • 0
    TI__Guru 68512 points

    Sheldon,

    Thanks for bringing this to our attention. I have a few questions.

    • When you say there is no output signal, do you mean on CANH and CANL, or RXD?
    • Is there any way to get oscilloscope pictures of TXD, CANH, CANL, and RXD?
    • How many units has this happened to?

    Let me know if you can get this information, it will make the debug much easier.

    Regards,

  • 0 in reply to Eric Hackett
    TI__Expert 8585 points

    Hi Eric,

    Q: When you say there is no output signal, do you mean on CANH and CANL, or RXD?

    A: They send data to TXD but nothing on CANL and CHAH, receiving is good

    Q: Is there any way to get oscilloscope pictures of TXD, CANH, CANL, and RXD?

    A: Please see attached

    Q: How many units has this happened to?

    A: Only one case. But it is the second in the history for this part number in this team.

    Below is the good and not good.

    BTW, it is the second time the meet this problem. This specific case happens after two years field running of an UPS.

    Thanks

    Sheldon

  • 0 in reply to Sheldon He
    TI__Guru 68512 points

    Sheldon,

    Thank you very much for all the information, this helps a lot.

    It looks like something is getting damaged in the path of TXD to bus driver. The RXD being a logic high confirms that the device isn't mistakenly being put in standby mode either. This might be the result of electrical overstress damage, are high voltage transients expected in the application environment? And are there any external protection components on the CAN bus?

    Can you also confirm the part number the customer is using? The SN65HVD1040 has been updated a few times, and I want to make sure I know which version the customer is using.

    Regards,

  • 0 in reply to Eric Hackett
    TI__Guru 62920 points

    Hi Sheldon,

    Have you been able to resolve this issue?  If not, have you been able to look further into Eric's questions above?

    Regards,
    Max